gridview update record

<asp:UpdatePanel ID="up2" runat="server">
        <contenttemplate>
            <asp:GridView ID="gv" runat="server" AutoGenerateColumns="false" 
                AutoGenerateEditButton="true" onrowediting="gv_RowEditing" 
                onrowcancelingedit="gv_RowCancelingEdit" onrowupdating="gv_RowUpdating" DataKeyNames="locationid">
                <columns>
                    <asp:TemplateField HeaderText="LocationID">
                        <itemtemplate>
                            <asp:Label ID="lbllocation" runat="server" Text='<%# Bind("locationid") %>'>
                        </itemtemplate>
                    
                    <asp:TemplateField HeaderText="RegionalGroup">
                        <itemtemplate>
                            <%# Eval("regionalgroup") %>
                        </itemtemplate>
                        <edititemtemplate>
                            <asp:TextBox ID="txtregional" runat="server" Text='<%# Eval("regionalgroup") %>'>
                        </edititemtemplate>
                    
                </columns>
            
            <asp:Label ID="lblmsg" runat="server">
        </contenttemplate>

protected void Page_Load(object sender, EventArgs e)
       {
           fillLocation();
       }

       protected void gv_RowEditing(object sender, GridViewEditEventArgs e)
       {
           gv.EditIndex = e.NewEditIndex;
           fillLocation();
       }

       protected void fillLocation()
       {
           Employees emp = new Employees();
           gv.DataSource = emp.GetLocations();
           gv.DataBind();

       }

       protected void gv_RowUpdating(object sender, GridViewUpdateEventArgs e)
       {
           int locationid = Int32.Parse(gv.DataKeys[e.RowIndex].Value.ToString());
           int intresult = 0;
           GridViewRow row=gv.Rows[e.RowIndex];

           TextBox tlo = (TextBox)row.FindControl("txtregional");
           Location lo = new Location();
           Employees emp = new Employees();
           try
           {
               lo.locationid = locationid;
               lo.regionalgroup = tlo.Text;
               intresult = emp.updatelocation(lo);
               if (intresult > 0)
               {
                   lblmsg.Text = "Record updated Sucessfully";
               }
               else
               {
                   lblmsg.Text = "Record couldnt updated";
               }

           }

           catch (Exception ex)
           {
               lblmsg.Text = ex.Message;
           }

           finally
           {
               lo = null;
               emp = null;
           }
           gv.EditIndex = -1;
           fillLocation();
       }

       protected void gv_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
       {
           gv.EditIndex=-1;
           fillLocation();
       }